Re: [Qemu-devel] [v2 RESEND 1/4] migration: defer migration_end & blk_mig_cleanup

[Juan Quintela <quintela@redhat.com>]

Liang Li <liang.z.li@intel.com> wrote:
> Because of the patch 3ea3b7fa9af067982f34b of kvm, which introduces a
> lazy collapsing of small sptes into large sptes mechanism, now
> migration_end() is a time consuming operation because it calls
> memroy_global_dirty_log_stop(), which will trigger the dropping of small
> sptes operation and takes about dozens of milliseconds, so call
> migration_end() before all the vmsate data has already been transferred
> to the destination will prolong VM downtime. This operation should be
> deferred after all the data has been transferred to the destination.
>
> blk_mig_cleanup() can be deferred too.
>
> For a VM with 8G RAM, this patch can reduce the VM downtime about 30 ms.
>
> Signed-off-by: Liang Li <liang.z.li@intel.com>
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Juan Quintela <quintela@redhat.com>

And the naming makes more sense even, thanks